<?php


namespace app\tool;

/**
 * 随机生成类
 */
class Random
{
	
	/**
	 * 生成数字和字母
	 *
	 * @param int $len 长度
	 * @return string
	 */
	public static function alnum($len = 6)
	{
		return self::build('alnum', $len);
	}
	
	/**
	 * 仅生成字符
	 *
	 * @param int $len 长度
	 * @return string
	 */
	public static function alpha($len = 6)
	{
		return self::build('alpha', $len);
	}
	
	/**
	 * 生成指定长度的随机数字
	 *
	 * @param int $len 长度
	 * @return string
	 */
	public static function numeric($len = 4)
	{
		return self::build('numeric', $len);
	}
	
	/**
	 * 生成订单号
	 * @return string
	 */
	public static function getOrderNumber()
	{
		return date('Ymd') . mb_strtoupper(uniqid());
	}
	
	
	/**
	 * 生成指定长度的无0随机数字
	 *
	 * @param int $len 长度
	 * @return string
	 */
	public static function nozero($len = 4)
	{
		return self::build('nozero', $len);
	}
	
	/**
	 * 能用的随机数生成
	 * @param string $type 类型 alpha/alnum/numeric/nozero/unique/md5/encrypt/sha1
	 * @param int $len 长度
	 * @return string
	 */
	public static function build($type = 'alnum', $len = 8)
	{
		switch ($type) {
			case 'alpha':
			case 'alnum':
			case 'numeric':
			case 'nozero':
				switch ($type) {
					case 'alpha':
						$pool = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
						break;
					case 'alnum':
						$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
						break;
					case 'numeric':
						$pool = '0123456789';
						break;
					case 'nozero':
						$pool = '123456789';
						break;
				}
				return substr(str_shuffle(str_repeat($pool, ceil($len / strlen($pool)))), 0, $len);
			case 'unique':
			case 'md5':
				return md5(uniqid(mt_rand()));
			case 'encrypt':
			case 'sha1':
				return sha1(uniqid(mt_rand(), true));
		}
	}
	
	/**
	 * 获取全球唯一标识
	 * @return string
	 */
	public static function uuid()
	{
		return sprintf(
			'%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
			mt_rand(0, 0xffff),
			mt_rand(0, 0xffff),
			mt_rand(0, 0xffff),
			mt_rand(0, 0x0fff) | 0x4000,
			mt_rand(0, 0x3fff) | 0x8000,
			mt_rand(0, 0xffff),
			mt_rand(0, 0xffff),
			mt_rand(0, 0xffff)
		);
	}
}
